Method and apparatus for attaching connective tissues to bone using a knotless suture anchoring device

ABSTRACT

A device for attaching connective tissue to bone has a longitudinal axis and comprises an annular toggle member and a body member disposed distally of the toggle member, such that there is an axial space between the toggle member and the body member. The toggle member is movable between an undeployed position wherein the toggle member has a smaller profile in a direction transverse to the axis and a deployed position wherein the toggle member has a larger profile in the direction transverse to the axis. When installed in a desired procedural site, in suitable bone, suturing material extends axially through a center aperture in the annular toggle member, without being secured to or contacting the toggle member. This approach permits a suture attachment which lies entirely beneath the cortical bone surface, and which further permit the attachment of suture to the bone anchor without the necessity for tying knots, which is particularly arduous and technically demanding in the case of arthroscopic procedures.

[0001] This application claims the benefit under 35 U.S.C. 119(e) of thefiling date of Provisional Application Ser. No. 60/273,137, filed onMar. 2, 2001, and is also a Continuation-in-part of U.S. applicationSer. No. 09/781,793, filed on Feb. 12, 2001, expressly incorporated byreference herein, and commonly assigned herewith.

BACKGROUND OF THE INVENTION

[0002] This invention relates generally to methods and apparatus forattaching soft tissue to bone, and more particularly to anchors andmethods for securing connective tissue, such as ligaments or tendons, tobone. The invention has particular application to arthroscopic surgicaltechniques for reattaching the rotator cuff to the humeral head, inorder to repair the rotator cuff.

[0003] It is an increasingly common problem for tendons and other soft,connective tissues to tear or to detach from associated bone. One suchtype of tear or detachment is a “rotator cuff” tear, wherein thesupraspinatus tendon separates from the humerus, causing pain and lossof ability to elevate and externally rotate the arm. Complete separationcan occur if the shoulder is subjected to gross trauma, but typically,the tear begins as a small lesion, especially in older patients.

[0004] To repair a torn rotator cuff, the typical course today is to doso surgically, through a large incision. This approach is presentlytaken in almost 99% of rotator cuff repair cases. There are two types ofopen surgical approaches for repair of the rotator cuff, one known asthe “classic open” and the other as the “mini-open”. The classic openapproach requires a large incision and complete detachment of thedeltoid muscle from the acromion to facilitate exposure. The cuff isdebrided to ensure suture attachment to viable tissue and to create areasonable edge approximation. In addition, the humeral head is abradedor notched at the proposed soft tissue to bone reattachment point, ashealing is enhanced on a raw bone surface. A series of small diameterholes, referred to as “transosseous tunnels”, are “punched” through thebone laterally from the abraded or notched surface to a point on theoutside surface of the greater tuberosity, commonly a distance of 2 to 3cm. Finally, the cuff is sutured and secured to the bone by pulling thesuture ends through the transosseous tunnels and tying them togetherusing the bone between two successive tunnels as a bridge, after whichthe deltoid muscle must be surgically reattached to the acromion.Because of this maneuver, the deltoid requires postoperative protection,thus retarding rehabilitation and possibly resulting in residualweakness. Complete rehabilitation takes approximately 9 to 12 months.

[0005] The mini-open technique, which represents the current growingtrend and the majority of all surgical repair procedures, differs fromthe classic approach by gaining access through a smaller incision andsplitting rather than detaching the deltoid. Additionally, thisprocedure is typically performed in conjunction with arthroscopicacromial decompression. Once the deltoid is split, it is retracted toexpose the rotator cuff tear. As before, the cuff is debrided, thehumeral head is abraded, and the so-called “transosseous tunnels”, are“punched” through the bone or suture anchors are inserted. Following thesuturing of the rotator cuff to the humeral head, the split deltoid issurgically repaired.

[0006] Although the above described surgical techniques are the currentstandard of care for rotator cuff repair, they are associated with agreat deal of patient discomfort and a lengthy recovery time, rangingfrom at least four months to one year or more. It is the above describedmanipulation of the deltoid muscle together with the large skin incisionthat causes the majority of patient discomfort and an increased recoverytime.

[0007] Less invasive arthroscopic techniques are beginning to bedeveloped in an effort to address the shortcomings of open surgicalrepair. Working through small trocar portals that minimize disruption ofthe deltoid muscle, a few surgeons have been able to reattach therotator cuff using various bone anchor and suture configurations. Therotator cuff is sutured intracorporeally and an anchor is driven intobone at a location appropriate for repair. Rather than thread the suturethrough transosseous tunnels which are difficult or impossible to createarthroscopically using current techniques, the repair is completed bytying the cuff down against bone using the anchor and suture. Earlyresults of less invasive techniques are encouraging, with a substantialreduction in both patient recovery time and discomfort.

[0008] Unfortunately, the skill level required to facilitate an entirelyarthroscopic repair of the rotator cuff is inordinately high.Intracorporeal suturing is clumsy and time consuming, and only thesimplest stitch patterns can be utilized. Extracorporeal knot tying issomewhat less difficult, but the tightness of the knots is difficult tojudge, and the tension cannot later be adjusted. Also, because of theuse of bone anchors to provide a suture fixation point in the bone, theknots that secure the soft tissues to the anchor by necessity leave theknot bundle on top of the soft tissues. In the case of rotator cuffrepair, this means that the knot bundle is left in the shoulder capsulewhere it can be felt by the patient postoperatively when the patientexercises the shoulder joint. So, knots tied arthroscopically aredifficult to achieve, impossible to adjust, and are located in less thanoptimal areas of the shoulder. Suture tension is also impossible tomeasure and adjust once the knot has been fixed. Consequently, becauseof the technical difficulty of the procedure, presently less than 1% ofall rotator cuff procedures is of the arthroscopic type, and isconsidered investigational in nature.

[0009] Another significant difficulty with current arthroscopic rotatorcuff repair techniques is shortcomings related to currently availablesuture anchors. Suture eyelets in bone anchors available today, whichlike the eye of a needle are threaded with the thread or suture, aresmall in radius, and can cause the suture to fail at the eyelet when theanchor is placed under high tensile loads.

[0010] There are various bone anchor designs available for use by anorthopedic surgeon for attachment of soft tissues to bone. The basiccommonality between the designs is that they create an attachment pointin the bone for a suture that may then be passed through the softtissues and tied, thereby immobilizing the soft tissue. This attachmentpoint may be accomplished by different means. Screws are known forcreating such attachments, but existing designs suffer from a number ofdisadvantages, including their tendency to loosen over time, requiring asecond procedure to later remove them, and their requirement for arelatively flat attachment geometry.

[0011] Another approach is to utilize the difference in density in thecortical bone (the tough, dense outer layer of bone) and the cancellousbone (the less dense, airy and somewhat vascular interior of the bone).There is a clear demarcation between the cortical bone and cancellousbone, where the cortical bone presents a kind of hard shell over theless dense cancellous bone. The aspect ratio of the anchor is such thatit typically has a longer axis and a shorter axis and usually ispre-threaded with a suture. These designs use a hole in the corticalbone through which an anchor is inserted. The hole is drilled such thatthe shorter axis of the anchor will fit through the diameter of thehole, with the longer axis of the anchor being parallel to the axis ofthe drilled hole. After deployment in to the cancellous bone, the anchoris rotated 90^(B) so that the long axis is aligned perpendicularly tothe axis of the hole. The suture is pulled, and the anchor is seated upagainst the inside surface of the cortical layer of bone. Due to themismatch in the dimensions of the long axis of the anchor and the holediameter, the anchor cannot be retracted proximally from the hole, thusproviding resistance to pull-out. These anchors still suffer from theaforementioned problem of eyelet design that stresses the sutures.

[0012] Still other prior art approaches have attempted to use a “poprivet” approach. This type of design requires a hole in the corticalbone into which a split shaft is inserted. The split shaft is hollow,and has a tapered plug leading into its inner lumen. The tapered plug isextended out through the top of the shaft, and when the plug isretracted into the inner lumen, the tapered portion causes the splitshaft to be flared outwardly, ostensibly locking the device into thebone.

[0013] Other methods of securing soft tissue to bone are known in theprior art, but are not presently considered to be feasible for shoulderrepair procedures, because of physicians' reluctance to leave anythingbut a suture in the capsule area of the shoulder. The reason for this isthat staples, tacks, and the like could possibly fall out and causeinjury during movement. As a result of this constraint, the attachmentpoint often must be located at a less than ideal position. Also, thetacks or staples require a substantial hole in the soft tissue, and makeit difficult for the surgeon to precisely locate the soft tissuerelative to the bone.

[0014] As previously discussed, any of the anchor points for suturesmentioned above require that a length of suture be passed through aneyelet fashioned in the anchor and then looped through the soft tissuesand tied down to complete the securement. Much skill is required,however, to both place the sutures in the soft tissues, and to tie knotswhile working through a trocar under endoscopic visualization.

[0015] There have been attempts to solve some of the problems that existin current anchor designs. One such approach is disclosed in U.S. Pat.No. 5,324,308 to Pierce. In this patent, there is disclosed a sutureanchor that incorporates a proximal and distal wedge component havinginclined mating faces. The distal wedge component has two suture threadholes at its base through which a length of suture may be threaded. Theassembly may be placed in a drilled hole in the bone, and when tensionis placed on the suture, the distal wedge block is caused to ride upagainst the proximal wedge block, expanding the projected area withinthe drilled hole, and locking the anchor into the bone. This approach isa useful method for creating an anchor point for the suture, but doesnot in any way address the problem of tying knots in the suture to fixthe soft tissue to the bone.

[0016] The problem of placing sutures in soft tissues and tying knots inan endoscopic environment is well known, and there have been attempts toaddress the problem and to simplify the process of suture fixation. Onesuch approach is disclosed in U.S. Pat. No. 5,383,905 to Golds et al.The patent describes a device for securing a suture loop about bodilytissue that includes a bead member having a longitudinal bore and ananchor member adapted to be slidably inserted within the bore of thebead member. The anchor member includes at least two axial compressiblesections which define a passageway to receive two end portions of asuture loop. The axial sections collapse radially inwardly uponinsertion of the anchor member within the bore of the bead member tosecurely wedge the suture end portions received within the passageway.

[0017] Although the Golds et al. patent approach utilizes a wedge-shapedmember to lock the sutures in place, the suture legs are passing throughthe bore of the bead only one time, in a proximal to distal direction,and are locked by the collapsing of the wedge, which creates aninterference on the longitudinal bore of the anchor member. Also, noprovision is made in this design for attachment of sutures to bone. Thedesign is primarily suited for locking a suture loop, such as is usedfor ligation or approximation of soft tissues.

[0018] A prior art approach that includes tissue attachment is describedin U.S. Pat. No. 5,405,359 to Pierce. In this system, a toggle wedge iscomprised of a two piece structure comprising a top portioncharacterized by the presence of a barbed tip and a bottom portion. Thesuturing material extends through apertures in each of the two toggleportions, and is maintained in position by means of a knot disposed inthe suture at a lower edge of the bottom toggle portion. To anchor thesuture into adjacent soft tissue, the two toggle portions are rotatedrelative to one another, as shown for example in FIG. 33. The disclosurestates that the device could be used to anchor suture in bone, as wellas soft tissue, if two embodiments are utilized in tandem.

[0019] However, the system is disadvantageous in that it is complex,difficult to manipulate, and still requires the tying of a knot in thesuture.

[0020] Another approach that includes bone attachment is described inU.S. Pat. No. 5,584,835 to Greenfield. In this patent, a two part devicefor attaching soft tissue to bone is shown. A bone anchor portion isscrewed into a hole in the bone, and is disposed to accept a plug thathas been adapted to receive sutures. In one embodiment, the suture plugis configured so that when it is forced into its receptacle in the boneanchor portion, sutures that have been passed through an eyelet in theplug are trapped by friction between the wall of the anchor portion andthe body of the plug portion.

[0021] Although there is some merit to this approach for eliminating theneed for knots in the attachment of sutures to bone, a problem withbeing able to properly set the tension in the sutures exists. The useris required to pull on the sutures until appropriate tension isachieved, and then to set the plug portion into the bone anchor portion.This action increases the tension in the sutures, and may garrot thesoft tissues or increase the tension in the sutures beyond the tensilestrength of the material, breaking the sutures. In addition, the minimalsurface area provided by this anchor design for pinching or locking thesutures in place will abrade or damage the suture such that the suture'sability to resist load will be greatly compromised.

[0022] A disclosure that incorporates bone attachment and eliminatesknot tying is set forth in U.S. Pat. No. 5,702,397 to Goble et al. Oneembodiment, in particular, is shown in FIG. 23 of that patent andincludes a bone anchor that has a threaded body with an inner cavity.The cavity is open to one end of the threaded body, and joins two lumensthat run out to the other end of the threaded body. Within the cavity isdisposed a gear, journaled on an axle. A length of suture is threadedthrough one lumen, around the gear, and out through the other lumen. Aball is disposed within the cavity to ride against a tapered race andostensibly lock the suture in place. What is not clear from the patentdisclosure is how the force D shown as the tension in the suture wouldlock the ball into the race. Although this embodiment purports to be aself-locking anchor adapted for use in blind holes for fixing suturesinto bone, the construct shown is complicated, and does not appear to beadequate to reliably fixate the suture.

[0023] U.S. Pat. No. 5,782,863 to Bartlett discloses a suture anchorincluding bone attachment, which simply comprises a conical sutureanchor having an anchor bore through which a length of suture isthreaded. The anchor is inserted into a bore within a portion of boneusing an insertion tool having a shape memory insertion end. As theanchor is inserted, because of its conical shape, it will re-orientitself by rotating in order to fit into the bore, bending the end of theinsertion tool. However, once the proximal edge of the bone anchorenters cancellous bone, the shape memory insertion end of the insertiontool will begin resuming its natural straight orientation, thus rotatingthe anchor back into its original orientation. The corners of theconical body thus protrude into the soft cancellous bone, and the anchorbody is prevented from exiting proximally from the bone bore through thehard cortical bone. The insertion tool is then removed.

[0024] The Bartlett patent approach, while innovative, isdisadvantageous to the extent that it involves the use of a unique andcomplex insertion tool, and can be difficult to deploy. It also does notpermit suturing of the soft tissue prior to anchoring the suture tobone, and thus does not permit tensioning of the suture to approximatethe soft tissue to bone, as desired, at the conclusion of the suturingprocedure. Additionally, in preferred embodiments, the suture is knottedto the anchor, a known disadvantage.

[0025] Yet another prior art approach is disclosed in U.S. Pat. No.5,961,538 to Pedlick et al. In this patent, a wedge shaped suture anchorsystem is described for anchoring a length of suture within a bore in abone portion, which comprises an anchor body having an offset sutureopening for receiving the length of suture therethrough, and forcreating an imbalance in the rotation of the device as it is inserted. Ashaft portion is utilized to insert the wedge-shaped anchor body intothe bone bore. Once the anchor body is in cancellous bone, below thecortical bone layer, the shaft is pulled proximally to cause the anchorbody to rotate, thereby engaging the corners of the anchor body with thecancellous bone. The shaft then becomes separated from the anchor body,leaving the anchor body in place within the bone.

[0026] The Pedlick et al. approach is conventional, in that the sutureis attached to desired soft tissue after it is anchored within the bone.Consequently, there is no opportunity to tension the suture, as desired,to optimally approximate the soft tissue to the bone upon completion ofthe surgical procedure. Additionally, the approach is complex andlimited in flexibility, since the suture is directly engaged with thebone anchoring body. There is also the possibility that the boneanchoring body will not sufficiently rotate to firmly become engagedwith the cancellous bone before the insertion tool breaks away from theanchor body, in which case it will be impossible to properly anchor thesuture.

[0027] U.S. Pat. No. 6,056,773 to Bonutti discloses a suture anchoringsystem which is somewhat similar to that disclosed by Pedlick et al. Acylindrical suture anchor body is provided which is insertable into abone bore, using a pusher member which pushes distally on the anchorbody from a proximal direction. As the anchor body proceeds into thebone bore, below the cortical bone surface, the suture extending throughthe lumen of the anchor body applies a proximal tensile force on theanchor body, to cause the anchor body to rotate relative to the pushermember, thereby anchoring the anchor body in cancellous bone. Of course,this system has similar disadvantages to those of the Pedlick et al.system, and requires the suture to be directly engaged with the boneanchoring body.

[0028] What is needed, therefore, is a new approach for repairing therotator cuff or fixing other soft tissues to bone, wherein both the boneand suture anchors reside completely below the cortical bone surface,there is no requirement for the surgeon to tie a knot to attach thesuture to the bone anchor, and wherein suture tension can be adjustedand possibly measured. The procedure associated with the new approachshould better for the patient than existing procedures, should savetime, be uncomplicated to use, and be easily taught to practitionershaving skill in the art.

SUMMARY OF THE INVENTION

[0029] The present invention solves the problems outlined above byproviding innovative bone anchor and connective techniques which permita suture attachment which lies entirely beneath the cortical bonesurface, and which further permit the attachment of suture to the boneanchor without the necessity for tying knots, which is particularlyarduous and technically demanding in the case of arthroscopicprocedures.

[0030] More particularly, in one aspect of the invention, a bone anchordevice is provided for attaching connective tissue to bone, which has alongitudinal axis and comprises a toggle member and a preferably tubularbody member disposed distally of the toggle member. An axial space ispresent between the toggle member and the body member. A connectingportion is disposed in the axial space, which joins the toggle member tothe body member.

[0031] In operation, when it is desired to deploy the inventive boneanchor device, the toggle member is movable, in a pivoting or rotationalfashion, between an undeployed position wherein the toggle member has asmaller profile in a direction transverse to the longitudinal axis,which is no wider than the transverse dimension or width of the bodymember and the hole into which the bone anchor device is disposed, and adeployed position wherein the toggle member has a larger profile in thedirection transverse to the axis, which is substantially larger than thewidth of the hole, so that the outer edges of the toggle member becomeembedded in the cancellous bone which lies beneath the cortical bonesurface, and so that there is no reasonable way, short of widening thehole through the cortical bone, of withdrawing the anchor proximally outof the hole.

[0032] When the toggle member is deployed, the connecting portiondeforms such that the axial space is reduced in length.

[0033] The connecting portion preferably comprises a one or more strutshaving proximal ends joined to the toggle member and distal ends joinedto the body member. In manufacture, the body member, struts, and togglemember, which is preferably annular and elliptical in configuration, mayall be fabricated from a single piece, such as a hypotube.

[0034] Preferably, the inventive toggle member is disposed at an acuteangle relative to the axis in the undeployed position, and is disposedin a substantially transverse orientation relative to the axis in thedeployed position.

[0035] The inventors have discovered that, due to potential cyclicloading effects during usage of the affected body part after completionof the medical procedure, it is advantageous to form at least theconnecting portion, and preferably the toggle member as well of abiocompatible relatively ductile material. In a presently preferredembodiment, the material comprises an annealed metal, such as stainlesssteel.

[0036] In a preferred embodiment, there is disposed a mandrel proximallyof the toggle member, and a casing extending through the toggle member.The mandrel, together with the body, is useful in actuating the togglemember from its undeployed position to its deployed position.

[0037] In another aspect of the invention, there is provided a boneanchor device for attaching soft tissue to bone, which device has alongitudinal axis and comprises a toggle member being rotatable from anundeployed position wherein the toggle member has a smaller profile in adirection transverse to the axis and a deployed position wherein thetoggle member has a larger profile in the direction transverse to theaxis. The toggle member has no structure for attaching suture materialthereto, since the suture material is to be attached to a body memberdisposed distally of the toggle member.

[0038] In yet another aspect of the invention, there is provided anapparatus for attaching connective tissue to bone, which apparatus has alongitudinal axis and comprises an annular toggle member and a bodymember disposed distally of the toggle member, such that there is anaxial space between the toggle member and the body member.Advantageously, the toggle member is movable between an undeployedposition wherein the toggle member has a smaller profile in a directiontransverse to the axis and a deployed position wherein the toggle memberhas a larger profile in the direction transverse to the axis. Wheninstalled in a desired procedural site, in suitable bone, suturingmaterial extends axially through a center aperture in the annular togglemember, without being secured to or contacting the toggle member.

[0039] In still another aspect of the invention, there is provided anapparatus for attaching connective tissue to bone, which apparatus has alongitudinal axis and comprises a toggle member and a body memberdisposed distally of the toggle member, such that there is an axialspace between the toggle member and the body member. The toggle memberis movable between an undeployed position wherein the toggle member hasa smaller profile in a direction transverse to the axis and a deployedposition wherein the toggle member has a larger profile in the directiontransverse to the axis. A connecting portion is disposed in the axialspace and joins the toggle member to the body member.

[0040] In another aspect of the invention, there is provided anapparatus for attaching connective tissue to bone, which comprises ananchor body having a longitudinal axis and having an anchoring structurefor fixing the anchor body within a body cavity. The anchor body has aproximal end, a distal end, and a lumen opening at the proximal end, andfurther includes a suture return member disposed therein such that alength of suture may be introduced into the lumen from the proximal end,looped around the suture return member, and passed out of the lumenthrough the proximal end. A suture locking plug is movable within thelumen from a first position to a second position, and a bone anchoringmember is attached to the anchor body, preferably at the proximal endthereof, and is movable between an undeployed position and a deployedposition. In preferred embodiments of the invention, the suture returnmember comprises a shaft or pin which may be either fixed or rotatable.The bone anchoring member preferably comprises a toggle member, which,in the undeployed position has a smaller profile in a directiontransverse to the longitudinal axis and in the deployed position has alarger profile in the direction transverse to the axis.

[0041] As noted supra, the toggle member is preferably disposedproximally of the anchor body such that there is an axial space betweenthe toggle member and the anchor body. When the toggle member is movedfrom the aforementioned undeployed position to the aforementioneddeployed position, the axial space is reduced in length. A connectingportion is disposed in the axial space and joins the toggle member tothe anchor body. The connecting portion preferably comprises a pair ofstruts having proximal ends joined to the toggle member and distal endsjoined to the anchor body.

[0042] In still another aspect of the invention, there is disclosed amethod of using suture to secure soft tissue, preferably a tendon, withrespect to a body cavity, preferably disposed in a portion of bone. Themethod comprises the steps of passing a length of suture materialthrough soft tissue so that a loop of suture material is disposed in thesoft tissue, resulting in two free ends, and providing an anchor bodyhaving an open proximal end and a lumen. A suture return member isdisposed in the anchor body. Additional steps include passing the twofree ends of the length of suture into the lumen of the anchor bodythrough the open proximal end, and looping them about the suture returnmember such that the two free ends of the suture extend proximally fromthe lumen through the open proximal end. The anchor body is fixed withrespect to the body cavity, and the loop of suture material is tensionedby pulling on one or both of the two free ends of the length of suture,to approximate the soft tissue with respect to the body cavity asdesired. A further step is to fasten the two free ends of the length ofsuture with respect to the anchor body without knots.

[0043] In preferred approaches, the step of fixing the anchor body withrespect to the body cavity comprises forming the body cavity, passingthe anchor body into the body cavity, and radially expanding anchoringstructure, preferably a deployable toggle member, on the anchor body.The anchoring structure is provided on a proximal end of the anchor bodyso as to engage the cortical layer of the bone and to prevent proximalremoval of the anchor body from the body cavity.

[0044] In yet another aspect of the invention, there is disclosed amethod of securing soft tissue to bone, comprising disposing an anchorbody having a longitudinal axis and having a length of suture securedtherein within a bore disposed in a portion of bone, and deploying atoggle member attached to a proximal end of the anchor body from anundeployed position wherein the toggle member has a smaller profile in adirection transverse to the axis to a deployed position wherein thetoggle member has a larger profile transverse to the axis. The togglemember fixes the anchor body axially relative to the portion of bone. Aconnecting portion joins the toggle member to the anchor body, and isdisposed in an axial space between the toggle member and the anchorbody. The aforementioned deploying step includes deforming theconnecting portion as the toggle member is moved from the undeployedposition to the deployed position.

[0045] The invention, together with additional features and advantagesthereof, may best be understood by reference to the followingdescription taken in conjunction with the accompanying illustrativedrawing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0046]FIG. 1 is a perspective view of a first preferred embodiment of abone anchor device constructed in accordance with the principles of thepresent invention;

[0047]FIG. 2a is a schematic plan view of the embodiment of FIG. 1, inits undeployed configuration;

[0048]FIG. 2b is a schematic plan view similar to FIG. 2a, showing theembodiment of FIG. 1 in its deployed configuration;

[0049]FIG. 3 is a perspective view of the bone anchor of FIG. 1,together with additional structure which is employed during installationof the bone anchor in a desired bone site;

[0050]FIG. 4 is schematic cross-sectional view of a typical proceduralsite, in a human shoulder, for which the present invention may beemployed;

[0051]FIG. 5 is a plan view, partially in cross-section, of theembodiment illustrated in FIG. 3, wherein the anchor is in itsundeployed configuration;

[0052]FIG. 6 is a plan view similar to FIG. 5, showing the anchor afterit has been deployed;

[0053]FIG. 7 is a cross-sectional view of a typical procedural site,illustrating a preferred method for closing the inventive repairprocedure after the anchor has been deployed in a suitable bone site;

[0054]FIG. 8 is a schematic plan view of an alternative embodiment ofthe inventive bone anchor;

[0055]FIG. 9a is a perspective view of another alternative embodiment ofthe inventive bone anchor;

[0056]FIG. 9b is a perspective view, similar to FIG. 9a, of yet anotheralternative embodiment of the inventive bone anchor;

[0057]FIG. 9c is a perspective view, similar to those of FIGS. 9a and 9b, of still another alternative embodiment of the inventive bone anchor;

[0058]FIG. 10A is a partial sectional view through the left shoulder ofa human as seen from the front showing the use of a minimally invasivesoft tissue to bone attachment system according to a presently preferredembodiment of the present invention;

[0059]FIG. 10B is an enlarged sectional view taken within the circledenoted 10B in FIG. 10A;

[0060]FIGS. 11A-11D are enlarged sectional views of the use of the softtissue to bone attachment system of FIG. 10A to reattach a rotator cufftendon;

[0061]FIGS. 12A-12C are partial longitudinal sectional views through adistal end of an exemplary soft tissue to bone attachment system of thepresent invention;

[0062]FIG. 13A is a perspective view of a combined suture lockingportion and bone anchor structure of the soft tissue to bone attachmentsystem of the present invention, showing a locking plug disengaged froman anchor body;

[0063]FIG. 13B is a partial longitudinal sectional view of the combinedsuture locking portion and bone anchor structure taken along line13B-13B of FIG. 13A;

[0064]FIG. 13C is an end elevational view of the combined suture lockingportion and bone anchor structure taken along line 13C-13C of FIG. 13B;

[0065]FIG. 14 is a perspective view of an anchor body of the combinedsuture locking portion and bone anchor structure of FIG. 13A;

[0066]FIG. 15 is a top plan view of the combined suture locking portionand bone anchor structure without the locking plug and an attachedactuation rod;

[0067]FIG. 16A is a perspective view of an exemplary suture lockingportion of the. soft tissue to bone attachment system of the presentinvention showing a locking plug disengaged from an anchor body;

[0068]FIG. 16B is a partial longitudinal sectional view of the suturelocking portion taken along line 16B-16B of FIG. 16A;

[0069]FIG. 16C is an end elevational view of the suture locking portiontaken along line 16C-16C of FIG. 16A;

[0070]FIG. 17A is a perspective view of the exemplary suture lockingportion of the soft tissue to bone attachment system of the presentinvention showing the locking plug engaged with the anchor body;

[0071]FIG. 17B is a partial longitudinal sectional view taken along line17B-17B of FIG. 17A;

[0072]FIG. 17C is an end elevational view taken along line 17C-17C ofFIG. 17A illustrating the locking plug clamping a length of sutureagainst an inner lumen of the anchor body;

[0073]FIG. 18A is a side elevational view of the deployed anchorstructure relative to the anchor body and locking plug therein;

[0074]FIG. 18B is an end elevational view of FIG. 18A;

[0075]FIG. 19 is a partial sectional view through the left humeral headof a human as seen from the front showing the use of an alternativeminimally invasive soft tissue to bone attachment system of the presentinvention;

[0076]FIG. 20A is a perspective view of a combined suture lockingportion and bone anchor structure of the present invention, showing analternative suture pulley structure; and

[0077]FIG. 20B is a cross-sectional view taken along lines 20B-20B ofFIG. 20A.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0078] Referring now more particularly to the drawings, there is shownin FIG. 1 a bone anchor 10, constructed in accordance with oneembodiment of the present invention, in its undeployed state. The boneanchor 10 is preferably comprised of a tubular or cylindrical body 12,which may, for example, be a hypotube, in which a series of diagonalcuts have been made at its proximal end 13 to create an annulargenerally elliptical angled toggle ring member 14. The cuts may be madeby using wire Electro-Discharge Machining (EDM) techniques, though manyother suitable known methods and materials for fabricating a generallytubular body and associated proximal toggle ring member may be utilizedas well. This toggle ring member 14 is generally oriented diagonallyrelative to a longitudinal axis 15 of the tubular anchor body 12. Thetoggle ring member 14 thus formed remains connected to the main portionof the tubular body 12 by two thin struts 16 which are situated suchthat they are substantially orthogonal to the orientation of the togglering member 14, and disposed at an acute angle θ relative to thelongitudinal axis 15 (FIG. 2a).

[0079] It is preferred that the anchor 10 be fabricated of biocompatiblematerials such as 300-series stainless steel (Type 304 or Type 316, forexample) or titanium, although suitable bioresorbable plastics maypotentially be used as well.

[0080]FIGS. 2a and 2 b are cross-sectional views of the bone anchor 10in its undeployed and deployed states, respectively. FIG. 2a illustratesmore clearly how the struts 16 connect the tubular body 12 to the togglering member 14. As can be seen in FIG. 2b, which illustrates the boneanchor in its deployed state, the struts 16 are designed so that theywill readily bend or deform to an orientation which is substantiallyorthogonal (transverse) to the axis 15 when a force 17 is applieddistally to the toggle ring member 14 and/or a force 18 is appliedproximally to the tubular body 12. As the thin struts 16 bend responsiveto the forces applied to the tubular body 12 and/or the toggle ringmember 14, the toggle ring member is compressed against the tubularanchor body 12 until it is in a fully deployed transverse positionrelative to the anchor body 12 and the struts 16 are disposed in arelatively flat transverse orientation between the anchor body 12 andthe deployed toggle ring member 14. The transverse orientation of thetoggle ring member 14 relative to the anchor body 12 allows the togglering member 14 to present an effective anchoring profile to the corticalbone surface when the bone anchor apparatus 10 is deployed, as shall bemore fully illustrated in the subsequent figures. Referring now to FIG.3, a hollow casing 19 has been inserted into the bone anchor 10, andattached to the anchor body 12 utilizing methods well known in the art,such as crimping, welding or the like, in order to secure the boneanchor 10 to the casing 19. In the embodiment shown herein asubstantially flat tongue 20 (see also FIG. 5) formed at the distal endof the casing 19, has been inserted into a slot 22 in the outer sidewallof the anchor body 12, and then welded at weldment 23 (FIG. 5) onto theoutside surface of the anchor body 12. The casing 19 is attached to thebone anchor 10 to provide a means for inserting the bone anchorapparatus into the surgical area arthroscopically. The casing 19 ispreferably of a hollow tubular shape at its proximal end 24 andpreferably has a half-cylindrical shape at its distal end 26. This halfcylindrical shape allows a length of suture 28 which has been threadedor stitched through desired soft tissue, such as a tendon, to be passedthrough the casing 19 and into the tubular body 12 through its openproximal end 13. The length of the suture 28 then preferably extendsdistally though the axial length of a lumen 29 of the body 12 and thenaround a suture return pin or pulley 30 at a distal end 31 of the body12. The pin 30 may be fixedly secured within the body 12, or mayalternatively be journaled to permit rotation. A further alternativeapproach is to secure the pin to the body 12 so that it may moveaxially. The suture returns through the lumen 29 in a proximaldirection, exiting the body 12 from its proximal end 13 and thentraversing the interior lumen of the hollow casing 19, exiting thehollow casing 19 from its proximal end 32 such that the free ends 33 ofthe suture 28 may be handled by the medical practitioner performing thesubject procedure. Referring still to FIG. 3, in the illustratedembodiment, a hollow mandrel 34 is placed over the proximal end of thecasing 19, in coaxial fashion, such that it may be moved in a distaldirection until it comes into contact with the toggle ring member 14connected to the proximal end of the body 12, thereby deploying suchtoggle ring member 14 as shall be shown in the following figures.

[0081] It should be noted, at this juncture, that, while a presentlypreferred means for securing the suture 28 to the bone anchor 10 hasbeen illustrated, any other suitable means for securing suture to boneanchors known in the art may be utilized in combination with theinventive bone anchor 10. For example, the suture 28 may merely beknotted to a provided eyelet on the body 12, or through a suturereceiving aperture or apertures on the anchor 10. Another alternativecould be to wrap the suture about a portion of the anchor 10 to secureit thereto.

[0082] Referring now in particular to FIGS. 4-6, the manner in which thebone anchor 10 is deployed into desired bone structure to secure softtissue to bone will be described. In FIG. 4, there is shown across-sectional view of a human shoulder 38 on the left side of the bodyas seen from the front of the body and which illustrates a rotator cufftendon 40 which is disposed across a humeral head 42. This illustrationis intended only to provide a simple structural overview of thephysiological elements involved in a typical situation involving therepair of a patient's rotator cuff, where it is to be desired that therotator cuff tendon 40 be reattached to a humeral head 42. It should benoted, of course, that the invention is applicable to many other typesof orthopedic repairs which involve the attachment of soft tissue toadjacent bone structure.

[0083] It is to be understood that, in this illustration, the rotatorcuff tendon 40 is not attached to the humeral head 42 at the interface44 between the two, as is typically the case when a patient's rotatorcuff has become damaged due to injury or overuse, and requires repair.The humeral head 42 is comprised of an outer surface of cortical bone 46and inner cancellous bone 48. A trocar 50 has been inserted into theshoulder 38 in proximity to the area where the rotator cuff tendon 40 isto be reattached to the humeral head 42, to allow for arthroscopicaccess, and a hole 52 has been made, preferably by drilling or punching,in the desired location through the cortical bone 46 and into thecancellous bone 48. A suture 28, is stitched in a suitable manner to therotator cuff tendon 40 which is to be secured to the humeral head 42.The stitching process may be accomplished by any known means, and anyknown suture stitch may be employed, the objective being to ensure asecure stitch so that the suture is not inadvertently separated from thetendon after completion of the repair procedure, necessitating re-entryto the surgical site. In preferred approaches, the suture is attached tothe soft tissue using a “mattress stitch”, which is well known in theart as being a particularly secure stitch which is unlikely to failpostoperatively. Preferably, a suturing instrument is inserted into thetrocar to perform the aforementioned suturing step. A preferred suturingapproach is taught in co-pending application Ser. No. 09/668,055,entitled Linear Suturing Apparatus And Method, filed on Sep. 21, 2000,expressly incorporated herein by reference and commonly assignedherewith. Of course, the inventive devices may also be utilized in anopen surgical procedure, if desired, wherein the sutures are manuallyplaced. Once the suturing process is completed, the free ends 33 of thesuture 28 are removed proximally through the trocar from the patient'sbody, together with the suturing instrument.

[0084] As shown particularly in FIG. 5, the free ends 33 of the suture28, while still outside of the patient's body, are then passed distallythrough the toggle ring member 14 and the casing 19, into the body 12,around the suture return pin 30, and then proximally out of the body 12and casing 19 where the free ends 33 may be manipulated by the surgeon.In FIG. 5, the anchor apparatus 10 is still in its undeployed state. Themandrel 34 has been inserted over the casing 19 such that it is disposedadjacent to the proximal end of the toggle ring member 14 prior todeployment. In the presently preferred method, the entire apparatus 10,including the body 12, the casing 19, and the mandrel 34, once loadedwith the suture 28, is then inserted through the trocar 50 and into thehole 52 in the humeral head 42 illustrated in FIG. 4.

[0085]FIG. 6 illustrates how the bone anchor is deployed after it hasbeen inserted into the hole 52 in the humeral head 42. The entireapparatus is inserted into the hole 52 a sufficient distance so that thetoggle ring member 14 is disposed just distally of the juncture betweenthe cortical bone 46 and the cancellous bone 48, just within thecancellous bone 48. Once so positioned, the bone anchor 10 may bedeployed within the cancellous bone 48 to lock the anchor 10 intoposition, thereby securely attaching the suture 28 to the humeral head42. To deploy the anchor 10, in a preferred method, the casing 19 iswithdrawn proximally. Because of its connection through joint formedbetween the tongue 20 and slot 22, this withdrawal force applied to thecasing 19 will also cause the body 12 to move in a proximal directionuntil it engages the distal side of the toggle ring member 14.Preferably, the mandrel 34 is maintained in a stationary position, sothat the continued proximal movement of the body 12 against the togglering member 14 results in the application of sufficient force on thestruts 16 to cause them to deform, thereby decreasing the axial spacingbetween the toggle ring member 14 and the proximal end of the body 12 toa relatively small distance. Referring again to FIGS. 2a and 2 b, thisforce applied against the toggle ring member 14 and struts 16 also causethe toggle ring member 14 to move in a pivoting fashion from anundeployed orientation, wherein the ring member 14 is disposed at anacute angle θ relative to the longitudinal axis 15 (FIG. 2a) to presenta smaller profile in a direction transverse to the axis 15, to adeployed orientation, wherein the ring member 14 is disposedsubstantially transversely to the axis 15 (FIG. 2b) in order to presenta larger profile in a direction transverse to the axis 15. Thisdeployment of the toggle ring member and consequent increase in thetransverse profile of the toggle ring member 14, causes the ends of thetoggle ring member 14 to push or dig into the soft cancellous bone justbeneath the surface of the cortical bone layer 46. Because the profileof the toggle ring member 14 in its deployed state is larger than thediameter of the hole 52, the apparatus is prevented from being pulledproximally out of the hole 52 after it has been deployed. The surfacearea of the toggle ring member 14 which is in contact with thecancellous bone 48 also prevents the apparatus from being moved eitherdistally or laterally after deployment.

[0086] As noted supra, it is preferable to maintain the mandrel 34 in astationary position, while moving the body 12 proximally to applydeployment force against the toggle ring member 14. The reason for thisis that by holding the mandrel 34 steady, the practitioner canaccurately control the depth at which the anchor 10 is deployed, so thatthe toggle ring member is deployed just distally of the distal surfaceof the cortical bone 46. If, instead, the mandrel were moved distally toapply force against the toggle ring member 14, ascertainment of thedepth of the deployed toggle ring member would be more difficult.However, if desired, the mandrel 34 may be moved distally against thetoggle ring member 14 while the casing 19 is maintained in a stationaryposition, thereby pushing the toggle ring member 14 distally until theresultant forces on the struts 16 cause them to deform. Still anotheralternative is to move the mandrel 34 distally, while at the same timemoving the body 12 proximally, to apply both a proximally directed and adistally directed force against the toggle ring member 14 and associatedstruts 16.

[0087] Ideally, as noted supra, once the toggle ring member or arm 14has been fully deployed, it will have rotated to an orientation fullytransverse (90 degrees displaced from) the axis 15. In such anorientation, the future loads on the arm 14, caused by axial forcesapplied to the anchor 10 during usage of the shoulder (i.e. duringrehabilitation therapy), will be columnar, and will thus not pose asubstantial risk of cyclic loading on the arm, with its attendant riskof eventual failure. However, in actual cases, it is unlikely that thearm 14 will always be oriented at precisely a 90 degree angle to theaxis 15, and it is therefore undoubtedly the case that the struts 16will see some degree of cyclic rotational loading during the healingprocess. Thus, Applicants have determined that arm 14 and struts 16should preferably be annealed during the manufacturing process, tosoften the material from which they are formed, thereby making thestruts more ductile, so that they can tolerate such loading withoutfailing.

[0088] Referring still to FIG. 6, the manner in which the casing 19 andmandrel 34 are removed from the procedural site after deployment of thebone anchor 10 is illustrated. Once the toggle ring member 14 is firmlypositioned in the cancellous bone 48 just below the cortical bonesurface 46, the casing 19 is withdrawn in a proximal direction. Thetongue 20 which is inserted through the slot 22 in the distal end 26 ofthe casing 19 is designed to break upon the application of a withdrawalforce of a predetermined strength on the casing 19, which force isconsiderably less than the force necessary to pull the deployed boneanchor 10 out of the hole 52. As a result, the bone anchor 10 remainsfirmly in place while the casing 19 and the mandrel 34 are removedthrough the trocar and out of the body. FIG. 7 provides an overall viewof the shoulder area and the bone anchor apparatus after the bone anchor10 has been deployed into the hole 52 in the humeral head 42 and as thecasing 19 and mandrel 34 are being removed through the trocar 50. Afterthe casing 19 and mandrel 34 are removed from the procedural site, thefree ends 33 of the suture 28 still extend through the trocar 50 and outof the body. The surgeon may then cinch and knot the free ends of thesuture 28 to secure the suture 28 to the bone anchor 10, and to snug thetendon 40 to the humeral head 42, as desired, or may employ a separatesuture-securing device. Many different methods or devices may beemployed to attach the suture 28 to the bone anchor device 10 or to aseparate suture securing device and these means will be well known tothose of ordinary skill in the art. The precise means of securing thesuture 28 is beyond the scope of this description.

[0089]FIG. 8 illustrates an alternative embodiment of the presentinvention. A bone anchor 110 is shown which is similar to the boneanchor described in connection with the above illustrations. Itcomprises a tubular or cylindrical body 112 and a toggle ring member114. The only significant difference in this alternative embodiment isthe absence of the thin struts 16 shown in the prior figures. In thisalternative embodiment the toggle ring member 114 is hinged directly tothe anchor body 112. It is deployed in the same manner using a casingand a mandrel as described above, but in this embodiment the toggle ringmember 114 simply bends at the hinge point 116 to move from itsundeployed position (illustrated in FIG. 8) in relation to the anchorbody 110 to its deployed position (not shown, but similar to thedeployed position of the first embodiment illustrated in FIG. 2b).

[0090] Additional alternative embodiments of the present invention maybe seen by referring to FIGS. 9a-c. FIG. 9a shows an embodimentconsisting of a substantially rectangular anchor 210 having a solidanchor body 212 and a solid rectangular member 214 attached by means ofa hinge 216 for deployment into the bone structure below the corticalsurface. Rather than using a casing that is inserted into the anchorbody as in the embodiments described above, the rectangular member 214is deployed by means of a mandrel 218 which pushes a first end of therectangular member 214 distally at the same time that a rod 220 attachedto the opposing end of the rectangular member 214 pulls that endproximally, thereby deploying the member 214 to an orientation having agreater transverse profile, as in the prior embodiments. The rod 220 isdesigned such that it will break away from the rectangular member 214when a proximal force is exerted on it after deployment of therectangular member 214 so that the rod 220 and the mandrel may beremoved.

[0091] The alternative embodiment shown in FIG. 9b is deployed inexactly the same manner as the embodiment shown in FIG. 9a. The onlydifference between the two embodiments is the configuration of theanchor 310, which has a tubular body 312 and a tubular toggle ringdeployment member 314.

[0092]FIG. 9c shows yet another alternative embodiment of a bone anchor410 with a hollow tubular body 412, and a hollow toggle ring deploymentmember 414 similar to the embodiment described above, supra, but whichis deployed by means of a mandrel 418 and rod 420 as with thealternative embodiments described in connection with FIGS. 9a and 9 b.

[0093] In FIGS. 10A through 20B are illustrated a preferred embodimentwhich includes a presently preferred suture anchoring approach. FIGS.10A-10B and 11A-11D are cross-sectional views through the left shoulderof a human as viewed from the front and illustrate the use of anexemplary suture anchor system 520 for repairing a rotator cuff tendoninjury. The rotator cuff tendon 522 is shown in its natural positionedoverlying the bulbous humeral head 524 of the humerus bone 526. Inrotator cuff injuries, the tendon 522 partially or completely separatesfrom its attachment point to the humeral head 524, which point ofattachment is typically located along an angled shelf, the greatertuberosity 528. In minimally invasive surgeries to repair the rotatorcuff injury, the surgeon threads one or more sutures through the rotatorcuff tendon 522 and anchors them to the greater tuberosity 528. Thesuture anchor system 520 of the present invention facilitates thislatter step of anchoring the sutures to the greater tuberosity 528.

[0094] With reference first to FIG. 10A, a generally tubular trocar 530provides a conduit through the soft tissue of the shoulder for thesuture anchor system 520 of the present invention. Typically, thesurgeon makes an incision or stab wound through the outer dermal layersof sufficient size to permit passage of the trocar 530 through skin andthe deltoid muscle into proximity with the humeral head 524. Varioustrocars and techniques for creating the approach passageway are knownand may be utilized with the present invention. In addition, more thanone incision and conduit may be necessary to perform the severalsuturing and anchoring steps.

[0095] After establishing one or more direct conduits to the humeralhead 524, the surgeon passes a length of suture through the soft tissueof the rotator cuff tendon 522 so that a loop 532 of suture material isembedded therein, as seen in FIG. 10B. The two free ends 534 a, 534 b ofthe length of suture are withdrawn from the patient and coupled to thesuture anchor system 520. The specifics of this coupling and subsequentmanipulation of the two free ends of the suture will be described morefully below. For the purpose of explaining the exemplary method of use,it is sufficient to understand that the two free ends 534 a, 534 b passinto a lumen at the distal end of the suture anchor system 520 andextend through the lumen in a proximal direction to a proximal end ofthe system to enable fixation or pulling of the suture ends. As seen inFIG. 10B, the two free ends 534 a, 534 b are shown projecting from aproximal end of the system. The system 520 further includes a pluralityof concentrically disposed cannulas or tubes as shown that perform theknotless suture anchoring operation. The interrelationship andfunctioning of these tubes will also be more fully explained below.

[0096] The exemplary system 520 as illustrated is particularly suitablefor anchoring a suture to a body cavity, specifically the humeral head524 as shown. When anchoring sutures to such a bone structure, aconventional technique is to first form a blind hole or cavity 540through the cortical layer 542 and into the soft cancellous matter 544,as seen in FIGS. 10A-10B and 11A-11D. The surgeon then positions asuture anchor 546 within the cavity 540 and deploys it such that itcannot be removed from the cavity.

[0097] The suture anchor 546 performs two functions: anchoring itselfwithin the body cavity and anchoring the sutures therein. In theillustrated embodiment, the former function is accomplished using anexpandable anchoring structure 548 located on the proximal end of thesuture anchor 546. The anchoring structure 548 is preferably the togglering 14 illustrated in FIGS. 1-7, and functions like a toggle bolt usedin ceiling fixtures, specifically expanding to a larger dimension in thecavity 540 beyond the hard cortical bone 542. In this manner, the sutureanchor 546 is prevented from being removed from the cavity 540 once theanchoring structure 548 is deployed. Although the present inventionillustrates a particular anchoring structure 548, which is similar tothe afore-described toggle ring 14, it should be noted that any similarexpedient will work. For example, a different toggle-like anchoringstructure may be used such as shown in co-pending application Ser. No.09/616,802, filed Jul. 14, 2000, the disclosure of which is herebyexpressly incorporated by reference. Alternatively, an anchoringstructure that expands into contact with the cancellous matter 544 maybe used.

[0098] The second function of the suture anchor 546 is the anchoring orfixation of the suture with respect to the suture anchor itself, withoutthe use of knots. Desirably, the particular manner of anchoring thesuture with respect to the suture anchor 546 permits easy adjustment ofthe length of suture between the suture anchor and the loop 532 formedin the soft tissue. This adjustment allows the surgeon to establish theproper tension in the length of suture for effective repair of the softtissue; reattachment of the rotator cuff tendon 522 in the illustratedembodiment. In this regard, FIG. 11D shows the fully deployed sutureanchor 546 after the free ends 534 a, 534 b have been placed in tensionand locked within the suture anchor. Although not shown, the remainingsteps in the procedure involve withdrawing the concentric tubes from thesurgical site and severing the free ends 534 a, 534 b close to thesuture anchor 546.

[0099]FIGS. 12A-12C are different partial longitudinal sectional viewstaken through the exemplary suture anchor system 520 of the presentinvention. The suture anchor 546 is seen in cross-section disposed in aclose-fitting relationship within a delivery tube 550. The delivery tube550, in turn, may be arranged to slide within a larger tube 552,sometimes known as an introducer tube, that includes a valve (not shown)on a proximal end to prevent fluid leakage therefrom. Alternatively,such a fluid leakage valve may be provided on the proximal end of thetrocar 530 seen in FIGS. 10A-10B.

[0100] The suture anchor 546 is defined by a generally tubular anchorbody 554 and an inner deployment tube 556 fits closely within a proximalend and is fastened therein. The exemplary suture anchor 546 is shownand described in greater detail below with respect to FIGS. 13A-14. Thedeployment tube 556 can also be seen on the right side in FIG. 12Aprojecting from the series of concentric tubes, with the free ends 534a, 534 b of the length of suture projecting therefrom. A die tube 558sized intermediate the delivery tube 550 and the deployment tube 556 isarranged for longitudinal displacement over the deployment tube 556. Inthe illustrated state of the system 520, the suture anchor 546 isundeployed within the delivery tube 550 and the die tube 558 ispositioned just proximal to the expandable anchoring structure 548. Afurther component of the suture anchor system 520 is a suture lockingplug 562 having an actuation rod 564 removably attached to a proximalend thereof and extending proximally within the deployment tube 556.

[0101]FIGS. 12A-12C all show the suture loop 532 extending transverselyfrom within the concentric tubes of the suture anchor system 520. Inthis regard, the delivery tube 550 is provided with an axial slot 565,the deployment tube 556 is provided with an axial slot 566, and the dietube 558 has an axial slot 567. The free ends 534 a, 534 b of the lengthof suture pass through these aligned axial slots 565, 566, 567 to theinterior of the deployment tube 556 that opens into the lumen 568 of thetubular body 554. The aligned axial slots 565, 566, 567 permit passageof the free ends 534 a, 534 b into the system 520 from a location midwayalong the concentric tubes, as indicated in FIGS. 10A-11D.

[0102] The various described components of the suture anchor system 520are relatively axially movable to deploy the suture anchor 546. Variousmeans are known to relatively displace concentric tubes a predetermineddistance and/or with a predetermined displacement force. For example,the concentric tubes may extend out of the trocar 530 to an actuationdevice in the form of concentric syringe bodies/finger tabs.Alternatively, the concentric tubes may be attached to relativelymovable parts in a gun-type handle, and actuated by triggers or othersuch levers. It is to be understood therefore that the present inventionis not limited by the particular actuation device on its proximal end,and no further description in this regard will be provided.

[0103] A more complete understanding of the exemplary suture anchor 546will be helpful prior to a detailed description of the structure andfunction of the concentric tubes to deploy the system. In this regard,FIGS. 13A-15 illustrate one embodiment of a suture anchor 546 isolatedfrom the remainder of the system and having the aforementioned tubularanchor body 554 and deployable anchoring structure 548. The anchor body554 defines a lumen 568 therewithin. FIGS. 13A and 13B also illustratethe suture locking plug 562 and attached actuation rod 564.

[0104] The anchor body 554 has the anchoring structure 548 on itsproximal end and a suture pulley or suture return member 570 disposed inproximity to its distal end. The aforementioned suture loop 532 isschematically illustrated out of the soft tissue for clarity, and itshould be understood that this suture loop 532 is embedded in the softtissue in actual use of the system. The free ends 534 a, 534 b of thelength of suture pass through an angled toggle ring 572 of the anchoringstructure 548 and into an open proximal end 574 of the lumen 568 formedwithin the tubular anchor body 554. The angled toggle ring 572 attachesto the proximal end 574 via a pair of plastically deformable struts 576.Both the toggle ring 572 and struts 576 are initially formed as aprojection of the tubular anchor body 554. After continuing in thedistal direction through the lumen of the anchor body 554, the free ends534 a, 534 b wrap around the suture return member 570 and traverse thelumen in the proximal direction to emerge from the angled toggle ring572 as shown.

[0105] As best seen in FIG. 13B, the actuation rod 564 extends into anopen distal mouth 576 of the anchor body 554 and through the lumen 568and angled toggle ring 572. The actuation rod 564 and four strands ofthe length of suture thus share the space within the lumen 568. Becauseof the relatively smaller size of the actuation rod 564 with respect tothe lumen 568, the length of suture may slide axially within the lumenwithout interference. It can therefore be seen that because the sutureloop 532 is embedded in soft tissue, pulling on the free ends 534, 534 bof the length of suture places the suture loop in tension.

[0106] Prior to a more exhaustive description of the function of thelocking plug 562 to perform the second function of the suture anchor 546(i.e., anchoring the length of suture with respect to the suture body554), use of the concentric tubes to deploy the anchoring structure 548will be explained. With reference again to FIGS. 12A-12C, the deploymenttube 556 can be seen attached within the lumen 568 of the anchor body554 using a tab 580. Of course, other means for attaching the deploymenttube 556 within the lumen of a body 554 may be provided, but a small tab580 bent inwardly from the anchor body 554 and welded or otherwisesecured to the deployment tube 556 is a suitable expedient. The tab 580is desirably provided at only one location around the circumferentialjunction between the deployment tube 556 and lumen 568 to facilitatesevering of this connection, although more than one attachment may beprovided. The tab 580 thus secures the deployment tube 556 within theanchor body 554 of the suture anchor 546, while both the die tube 558and actuation rod 564 can freely slide with respect to the anchor body554.

[0107] After positioning the delivery tube 550 in proximity with thepreformed body cavity 540 as seen in FIGS. 10A and 10B, the surgeonadvances the deployment tube 556 having the suture anchor 546 attachedthereto into the cavity. The suture locking plug 562 and die tube 558advance along with the deployment tube 556, and the resultingconfiguration is seen in FIG. 10B.

[0108] Using a depth measurement, or visualization technique, thesurgeon insures that the suture anchor 546, and in particular theanchoring structure 548, has been inserted past the hard outer layer ofcortical bone 542. The anchoring structure is then expanded as seen inFIG. 11A. To accomplish this, the die tube 558 contacts the angledtoggle ring 572 and forces it into an orientation that is generallyperpendicular with respect to the axis of the suture anchor 546. Withreference to FIGS. 12A-12C, the die tube 558 is desirably heldstationary while the deployment tube 556 having the suture anchor 546attached thereto is pulled in a proximal direction. Again, the relativemovement of these tubes can be accomplished using a handle or otherdevice exterior to the patient's body. Pulling on the deployment tube556 forces one side of the angled toggle ring 572 against the generallycircular distal mouth of the deployment tube 556 which deforms thestruts 576 as the toggle ring 572 moves into a perpendicularorientation.

[0109] After the anchoring structure 548 is deployed, further pulling onthe deployment tube 556 detaches it from the suture anchor 546.Specifically, the aforementioned welded tab 580 severs at apredetermined pulling force. The die tube 558 remains in place in itsfixed position, and provides a reaction force against the suture anchor546. The deployment tube 556 is then pulled free and retracted out ofthe way, as indicated in FIG. 11B. At this stage, the suture anchor 546is secured with respect to the body cavity, but the length of suturepassing therethrough remains free to be axially displaced.

[0110] Now with specific reference to FIGS. 12A-12C, the path of thelength of suture through the suture anchor system 520 will be described.The suture loop 532 is seen projecting upward from the system, but itagain should be noted that this loop is embedded in soft tissue in useof the system. The two free ends 534 a, 534 b extend through an axialslot 590 in the delivery tube 550, and through an axial slot 590 in thedeployment tube 556 into lumen 568 of the suture can 546. As best seenin FIG. 12C, the free ends pass through the lumen 568 and around theaforementioned suture return member 570. The free ends then travel in aproximal direction through the lumen 568 and through the lumen of thedeployment tube 556 to emerge from proximal end of the system. Becausethe suture loop 532 is embedded in soft tissue, pulling on both of thefree ends 534 a, 534 b, or pulling on one end while holding one fixed,will create tension in the length of suture. The suture return member570 provides relatively little resistance to sliding of the length ofsuture therearound, and thus this tensioning can be accomplishedrelatively easily.

[0111] In one embodiment, the suture return member 570 comprises a pinoriented transversely to the axis of the suture anchor 546 and locatedalong a sidewall thereof. As seen best in FIG. 13A, the pin may span anaxial slot 600 in a sidewall of the anchor body 554 so that the freeends 534 a, 534 b of length of suture can pass out through the slot andaround the pin. Alternatively, two axially spaced holes with chamferedor rounded edges may be formed in the sidewall of the anchor body 554through which the free ends 534 a, 534 b can be threaded and fixed. Ofcourse, numerous structures are contemplated that provide the functionof the illustrated pin-type suture return member 570. Moreover, insteadof being a fixed structure, the suture return member 570 can be arrangedto swivel or otherwise move to facilitate sliding motion of the freeends 534 a, 534 b therearound. In a specific example, the pin-typesuture return member 570 can be formed separately from the anchor body554 and inserted within a pair of facing holes in the edges of the slot600. In this manner, the pin-type suture return member 570 rotateswithin the holes, thus reducing friction between the free ends 534 a,534 b and the suture return member.

[0112] The step of tensioning the length of suture is seen in FIG. 11C,wherein the suture locking plug 562 remains in its initial positionspaced from the anchor body 554. Adjustment of the length of the suturebetween the suture anchor 546 and the loop 532 is very important toensure proper fixation of the rotator cuff tendon 522 with respect tothe humeral head 524. If the suture is pulled too tightly, the rotatorcuff tendon 522 may be unduly stressed, and the loop 532 may even pulledfree from the tendon. On the other hand, if the suture is too loose, thegoal of reattaching the tendon 522 in its proper location will becompromised.

[0113] Once the surgeon has established proper tension on the suture,the suture is anchored with suspect to the anchor body 554. This is doneby displacing the suture locking plug 562 in a proximal direction sothat it is forced into the lumen 568. The plug 562 includes a generallycylindrical shaft 602 with a bullet-shaped proximal nose 604 to helpprevent its catching on a distal mouth 605 of the anchor body 54.Proximal displacement of the actuation rod 564 from outside the bodycauses proximal movement of the attached plug 562.

[0114]FIGS. 16A-17C show the anchor body 554 without the aforementionedanchoring structure 548, for clarity. These views illustrate themovement of the suture locking plug 562 into the lumen 566, andconsequent locking of the length of suture therein. The diameter of thecylindrical shaft 602 of the plug 562 is sized to be slightly smallerthan the inner diameter of the lumen 568. As seen in FIGS. 17B and 17C,the diameter of the cylindrical shaft 602 is such that it compresses thefour strands of the length of suture against the lumen 568. The lockingplug 562 is dimensioned to compress or “crush” the length of suture inthe lumen 568 and interfere with its axial movement therethrough. Theamount of compression may be measured by the amount of pull force on thesuture necessary to move it once the plug is in position. Desirably, thepull force is in a range that would exceed the USP (United StatesPharmacopeia) Standard knot pull strength (USP 24) of the suture used.In the specific case of #2 braided polyester suture, this knot pullstrength is approximately 3.5 Kgf. In practice, however, the knot pullstrength of commercially available #2 braided polyester suturesapproaches 14 Kgf.

[0115] Proximal displacement of the locking plug 562 within the anchorbody 554 is desirably limited by a positive stop. In the illustratedembodiment, a stop flange 610 projects outwardly from the cylindricalshaft 602 at its distal end. The stop flange 610 slides within an axialslot 612 at the distal end of the anchor body 554 that terminates at aslot end 614. Although not shown in the figures, proximal movement ofthe locking plug 562 is ultimately restricted by contact between thestop flange 610 and the slot end 614. Of course, other configurationsthat provide a positive stop to proximal movement of the locking plug562 are contemplated. For example, rather than dimensioning the lockingplug 562 to be larger than the lumen 568 of the anchor body 554 (asexhibited by the stop flange 610), a stop surface may project inwardlyfrom the lumen 568 to interfere with movement of the plug 562.

[0116] One advantage provided by the present invention is the ability totighten a suture loop embedded within soft tissue to a predeterminedtension, and then locked to the suture within a suture anchor withouteven slightly altering that tension. As best seen in FIG. 17B, thelocking plug 562 is shown partly inserted within the tubular body 554during the step of being pulled proximal by the actuation rod 564 asindicated by the movement arrows 616. The free ends 534 a, 534 b of thelength of suture extend around the suture return member 570, havingpreviously been tensioned to a predetermined amount. Proximal movementof the locking plug 562 acts on all four strands of the length of suturewithin the lumen of the tubular body 554, and thus imparts equalfrictional forces to all of the strands tending to urge them in aproximal direction. Because the four strands loop around the suturereturn member 570, with two coming and two going, these frictionalforces cancel out such that the free ends 534 a, 534 b do not migratewithin the tubular body 554. Because the suture return member 570 andtubular body 554 remain fixed with respect to the suture loop 532 (whichis embedded within the soft tissue), the predetermined tension withinthe loop remains constant during the suture locking step.

[0117] In a further example, as seen in FIGS. 18A and 18B, deformationof the angled toggle ring 572 forces it into an oval shape at theproximal end 574 of the anchor body 554. This oval shape may have aminor dimension that is smaller than the diameter of the cylindricalshaft 602, or more typically the struts 576 may be bent into the path ofthe shaft 602, thus presenting an interference and a positive stop tothe shaft movement. Alternatively, the actuation rod 564 may be bentback upon the exterior surface of the locking plug 562 to form the stopsurface.

[0118] Once the suture locking plug 562 has been positively stopped, theactuation rod 564 may be detached therefrom. As seen in the figures, theactuation rod 564 extends within a through bore in the cylindrical shaft602 and includes a frangible point 620 in that bore. The segment of theactuation rod distal to this frangible point 620 is secured within thebore in a conventional manner, such as with crimping indicated at 622 inFIG. 16A. The die tube 558 may be used as a reaction force against theanchor body 554 while the actuation rod 564 is pulled in the proximaldirection, causing the frangible point 620 to fracture. The finalconfiguration is seen in FIG. 11D.

[0119] As mentioned above, the exemplary structure for locking suturesrelative to a body cavity may be utilized in a variety of anatomicalenvironments. For instance, FIG. 19 shows an alternative surgicaltechnique for using a combined suture anchor 546′ and anchoringstructure 548′ to repair a rotator cuff tendon 522. In this embodiment,rather than forming a blind cavity within the humeral head 524, thesurgeon forms a cavity 630 that transects the greater tuberosity 528 andopens through the cortical layer 542 at both ends. After embedding theloop 532 of suture material within the rotator cuff tendon 522, the freeends 534 a, 534 b are inserted into and threaded through the cavity 630.The ends 534 a, 534 b are then passed through the lumen formed withinthe combined suture anchor 546′ and anchoring structure 548′, whichcombination is then inserted as shown into the cavity 630. The free ends534 a, 534 b of suture are then tightened to the prescribed level andsecured within the suture anchor 546′. It should be noted that thecombined suture anchor 546′ and anchoring structure 548′ may beconfigured somewhat differently to permit the aforementioned tighteningstep, though the suture locking steps are preferably accomplished in thesame manner as described above; namely, with a suture locking plugcompressing the length of suture within the suture anchor 546′.Furthermore, the anchoring structure 548′ contacts the exterior of thecortical bone rather than the interior as described above.

[0120]FIGS. 20A and 20B illustrate an alternative suture anchor 640 ofthe present invention having a body cavity anchoring structure 642 on aproximal end. A length of suture is shown having a loop 644 and a pairof free ends 646 a, 646 b passing through the anchoring structure 642and through a lumen 648 of a generally tubular body 650 of the sutureanchor 640. In a distal portion of the tubular body 650, the free ends646 a, 646 b pass out of the lumen 648 through a first aperture 652 aand re-enter the lumen through a second aperture 652 b located distallyfrom the first aperture. As illustrated, the lumen 648 in the region ofthe apertures 652 a, 652 b is only partly defined by a semi-cylindricalextension of the tubular body 650, but other arrangements having a morecomplete lumen at this location are within the scope of the presentinvention.

[0121] With reference to FIG. 20B, the apertures 652 a, 652 b are shownto be rounded to reduce abrasion on the suture free ends 646 a, 646 b.In addition, the bridge portion 654 of the tubular body 650 thatseparates the apertures 652 a, 652 b defines a suture return memberstructure, much like the suture return member 570 (FIG. 17B) describedabove in the earlier embodiment. That is, the suture free ends 646 a,646 b can easily slide with respect to the bridge portion 654,especially because of the rounded corners, to permit tightening of thesuture loop 644 prior to locking the length of suture within the tubularbody 650. The length of suture may be locked within the tubular body 650using a locking plug as described above, or with another similarexpedient.

[0122] It is to be understood that the figures of the bone and anchorsseen above are purely illustrative in nature, and are not intended toperfectly reproduce the physiologic and anatomic nature of the humeralhead as expected to be seen in the human species, nor to limit theapplication of the inventive embodiments to repair of the rotator cuff.The invention is applicable to many different types of proceduresinvolving, in particular, the attachment of connective or soft tissue tobone. All of the terms used herein are descriptive rather than limiting,and many changes, modifications, and substitutions may be made by onehaving ordinary skill in the art without departing from the spirit andscope of the invention, which is to be limited only in accordance withthe following claims.

1. A bone anchor device for attaching connective tissue to bone, saiddevice having a longitudinal axis and comprising: a toggle member; abody member disposed distally of the toggle member, such that there isan axial space between said toggle member and said body member; and aconnecting portion disposed in said axial space and joining said togglemember to said body member; said toggle member being movable between anundeployed position wherein said toggle member has a smaller profile ina direction transverse to said axis and a deployed position wherein saidtoggle member has a larger profile in said direction transverse to saidaxis; and said connecting portion deforming when said toggle member ismoved from said undeployed position to said deployed position such thatsaid axial space is reduced in length.
 2. The bone anchor device asrecited in claim 1, wherein said body member is tubular.
 3. The boneanchor device as recited in claim 1, wherein said connecting portioncomprises a strut having a proximal end joined to said toggle member anda distal end joined to said body member. 4-6. (Canceled)
 7. The boneanchor device as recited in claim 1, wherein said toggle member isdisposed at an acute angle relative to said axis in said undeployedposition, and is disposed in a substantially transverse orientationrelative to said axis in said deployed position.
 8. The bone anchordevice as recited in claim 1, wherein said connecting portion is formedof a biocompatible relatively ductile material.
 9. The bone anchordevice as recited in claim 8, wherein said biocompatible relativelyductile material comprises annealed metal.
 10. The bone anchor device asrecited in claim 1, wherein a transverse dimension of said toggle memberin the undeployed position is substantially the same or less than atransverse dimension of said body member.
 11. The bone anchor device asrecited in claim 10, wherein said transverse dimension of said togglemember in the deployed position is substantially greater than thetransverse dimension of said body member.
 12. The bone anchor device asrecited in claim 1, and further comprising a mandrel disposed proximallyof said toggle member. 13-14. (Canceled)
 15. A bone anchor device forattaching soft tissue to bone, said device having a longitudinal axisand comprising a toggle member being rotatable from an undeployedposition wherein said toggle member has a smaller profile in a directiontransverse to said axis and a deployed position wherein said togglemember has a larger profile in said direction transverse to said axis,said toggle member having no structure for attaching suture materialthereto.
 16. The bone anchor device as recited in claim 15, and furthercomprising a body member disposed distally of said toggle member, suchthat there is an axial space between said toggle member and said bodymember, and a connecting portion disposed in said axial space andjoining said toggle member to said body member.
 17. The bone anchordevice as recited in claim 16, wherein said connecting portion deformswhen said toggle member is rotated from said undeployed position to saiddeployed position, such that said axial space is reduced in length. 18.The bone anchor device as recited in claim 16, wherein said connectingportion comprises a strut having a proximal end joined to said togglemember and a distal end joined to said body member. 19-24. (Canceled)25. Apparatus for attaching connective tissue to bone, said apparatushaving a longitudinal axis and comprising: a toggle member; a bodymember disposed distally of the toggle member, such that there is anaxial space between said toggle member and said body member; said togglemember being movable between an undeployed position wherein said togglemember has a smaller profile in a direction transverse to said axis anda deployed position wherein said toggle member has a larger profile insaid direction transverse to said axis; and a connecting portiondisposed in said axial space and joining said toggle member to said bodymember. 26-44. (Canceled)
 45. A device for anchoring a suture to tissueor bone, comprising: a first component adapted to be embedded in boneand having at least one passage therein; a suture having at least aportion extending from the at least one passage; and a second componentreceivable within the first component such that the first and secondcomponents are effective to retain the suture therebetween bycompression.